Organic electroluminescent display device, due to advantages such as high brightness, high contrast ratio, wide viewing angle and fresh color, is widely concerned and gradually applied in various fields at present.
In the organic electroluminescent display device, an array substrate is provided with a source-drain electrode metal layer in a non-display area and the source-drain electrode metal layer is employed to connect data lines in a display area with an outside drive circuit. In addition, in the organic electroluminescent display device, the display area of the array substrate comprises a display electrode and the display electrode for example is a metal layer, a transparent electrode layer, or a combination of the metal layer and the transparent electrode layer. The metal layer for example is formed of silver or silver alloy, and the transparent electrode layer for example is formed of transparent conductive oxide (such as ITO). In a process of forming the display electrode by etching (for example, a wet-etching is generally employed), primary cell effect is likely to occur so that the source-drain electrode metal layer in the non-display area is damaged, hence reducing yield rate of display devices. So-called primary cell effect (galvanic effect) refers to a phenomenon that metals with different activity or metal and other conductive material (such as non-metal material or oxides) having different activity are immersed into electrolyte solution (for example, acidic substance such as sulfuric acid, hydrogen peroxide) and a redox reaction occurs, so that the metal with a higher activity (namely, with a strong reducibility) is oxidized and corroded.
To solve the above problem, it is considered to employ special material, such as titanium or a laminate structure of titanium and other metals, to form the source-drain electrode metal layer, so as to increase anti-corrosion property of the source-drain electrode metal layer. However, it is of high cost to employ titanium or the laminate structure of titanium and other metals; in addition, it is needed to develop new deposition and patterning process, which further increases manufacturing cost.